Driving past Parliament House in New Delhi nowadays, one gets teasing glimpses of the roof of a building that has just come up in its immediate vicinity. A high boundary wall hides from public view most of the new Parliament Library building, the latest addition to the complex. What makes this an important architectural landmark is of course the building's obvious symbolic stature, and its location on the acropolis as it were. But its real significance lies in the fact that on this charged site, suffused with colonial architectural associations, a prominent and well-regarded architect has attempted to address the perennial problem confronting Indian practitioners of his craft: how do you seek out your roots and yet be modern?

Though many would regard this as a quixotic quest, one way or another, consciously or otherwise, architects in India continue to wrestle with the problem of a collective architectural identity in every project they undertake. In a post-colonial, modernising society, under constant pressure from the forces of globalisation, the need to define a regional identity gets accentuated, and is naturally foregrounded in the production of local architecture. In addition to the many problems that architects face in India, the search for "Indianness" therefore becomes, in Edward Said's words, their "uniquely punishing destiny". But many among the post-Independence generation of architects, particularly those from the 1960s and 1970s, recognised the creative potential of this imperative, and produced compelling works by addressing it. This building is of that genre.

The noted architectural historian Kenneth Frampton memorably termed the exemplary works of this genre - "critical regionalism" because the tenets of universal modernism were critically mediated by the local architects' familiarity with their roots - the indigenous building traditions and practices. Among the handful who have pursued this strategy with great success is Raj Rewal, the architect of the Parliament Library.

Viewing the architecture of India from this perspective enables one not only to understand the architecture of the Parliament Library but also to distinguish between architecture with gravitas and that without, to tell the work of a serious practitioner from that of a journeyman. When, for example, one evaluates another important library that was completed recently in New Delhi in this light one begins to understand why, in spite of its equally important context and impressive image, it falls short. This building, the Indira Gandhi National Centre for the Arts (IGNCA) Library, built on a prominent site flanking Lutyen's grand Central Vista, was designed by an American architect, Ralph Lerner, who self-consciously attempted to be both modern and Indian in his design. However, viewing this building through the filter of critical regionalism, it becomes apparent that Lerner's attempt to give the building an Indian identity merely resulted in a pastiche.

SO what makes Rewal's design more authentic? One reason, though by no means a sufficient one, is that one knows his architectural pedigree and in the Parliament Library he develops themes that he has pursued with great rigour earlier. Rewal's long-term strategy has been to transform traditional elements of architecture for contemporary deployment, not merely transfer their images as Lerner has done in the IGNCA library. The other related reason is that even as Rewal fulfils the functional requirements, he seeks to do so at a deeper level. It is the deep structure of his architectural methods that set his work apart from that of Lerner's, or for that matter any other architect in India.

Rewal explains that his aim in this project was to seek a low-key architectural expression signifying "sagacity, even spiritual elegance" rather than to "attempt to compete with the power of the Parliament". He draws the analogy of the relationship between a guru and the king to describe his vision for the design of the library (the guru) and its relationship to Parliament house (the king). These metaphors may sound trite, and are of course meaningless unless they are credibly translated into the architecture of the building. However, in the experience of the building, one does feel the deep resonance of Rewal's architectural intent.

The building does not rise above the podium level of Parliament House. It is composed of a variety of symmetrically structured formal spaces and volumes that endow the main movement route and link the major functions of the library with an almost ritual character. Interspersed with landscaped courtyards and four-storey atriums, the juxtaposing of indoor and outdoor spaces in this labyrinthine building is formally developed and elegant. In this manner, Rewal has subtly modulated the experience of daylight in all the public spaces, and it even reaches the second basement. The plan of the library resembles a square mandala with nine interlinked nodal points, where each node is a functional entity. However, one corner of the mandala is missing because of the constraints of placing the square form on a triangular site.

Rewal invariably derives the spatial configuration of his buildings from historical precedents, and to those familiar with his work the formal structure of this building is almost formulaic. He explains that his model in this case was the Ranakpur temple in Rajasthan. The link is at best ephemeral. The model is merely a device used to develop a suitable spatial pattern for the disposition of the functional elements of the building.

In the design of the Asiad Village, New Delhi, for example, Rewal applied the lessons he learnt studying the town morphology of Jaisalmer; in other projects he has used the traditional courtyard of the haveli as a model. Other architects also employ similar strategies, but Rewal's success as a 'modern' and 'Indian' architect can be attributed in no small measure to the authoritative manner in which he achieves the transformation of timeless historical models to suit the exigencies of the particular architectural programme. But of course that is not all that distinguishes his architecture, or this building.

Rewal also employs innovative structural systems to develop the distinctive forms that characterise many of his buildings. This is an important characteristic of modernism that many people fail to appreciate when they focus their attention on the looks of his buildings: the look is often the result of the structural system he employs in his design. At Pragati Maidan, New Delhi, he developed reinforced concrete space frame structures to produce a jali-like effect on the exterior envelop of large exhibition halls. This was the result of an improbable structural decision to construct the space frame structure in reinforced concrete instead of steel as is customary.

In the Parliament Library Building, Rewal has continued to explore unconventional building materials and structural systems, and use them in innovative ways. Jose Kurien, the structural engineer from the Central Public Works Department (CPWD), describes his role in the realisation of this building by quoting Peter Rice, the engineer who worked with architects Richard Rogers and Renzo Piano on the design of the revolutionary Pompidou Centre in Paris, by saying that the architect's response was primarily creative, whereas the engineer's was primarily inventive. A number of engineering inventions were required to realise the architectural design of this building, and one hopes that this information will be widely disseminated in the profession.

This building, perhaps for the first time in India, uses tubular steel lattices supported on steel ring beams to span a space of 30 to 40 metres lightly and elegantly. These lattices provide the framework to fix the shallow domes, some made of glass, and others of light-weight, fibre-reinforced concrete. It is these domes that one sees from the outside, above the high compound wall.

What is remarkable about this building is that it has been constructed within the constraints of the CPWD tendering system. A legacy of colonial governance, this system is normally administered stodgily by bureaucratic-minded engineers who effortlessly blunt the imagination of ordinary architects. But Raj Rewal has time and again been able to overcome such hurdles.

Of course, this was a very special project. Rewal points out that like Kurien, the CPWD engineers who were assigned this project were exceptionally open minded and willing to do things differently. Financial constraints were relaxed, as also many of a procedural character. The government permitted the use of extravagant building materials and the import of special structural elements and equipment. It let Kurien consult foreign experts to design the innovative roof systems. In the end, the cost of the project, including all the services, interior finishes and furniture, was close to Rs.200 crores, which works out to about Rs.33,000 a square metre. This is not a mean sum of money to spend to provide reading facilities for parliamentarians - and a few select scholars.

However, one would not like to give the impression that the success of this building is solely on account of the money spent on its construction. In fact, the loose purse-strings may have resulted in the interiors in parts resembling a five-star hotel lobby, mitigated only partially by Rewal's innate sense of proportion and taste.

What remains memorable in the experience of this building is the architect's masterly control of daylight, the well-modulated spatial experience and the contrast he achieves between the solidity of sandstone-faced external walls and the delicate, almost tracery-like steel structural system that supports the long-span roofs. It is simultaneously unmistakably 'Indian' and 'modern'. It is a pity that the ruling paranoia about security considerations will keep this building from public view. Perhaps the government should consider opening such buildings to the public for a limited period of time every year following the practice in many European countries. It will contribute immensely to the appreciation of contemporary architectural culture in India.